Lock



May 8, 1934. G RUBNER 1,957,851

LOCK

Filed Sept. 10, 1931 2 Sheets-Sheet l IN W. N TOR 171/470 [Z FL/ZWEP A T TOR/V5,

Patented May 8, 1934 UNETED STATES PATENT OFFICE LOCK Application September 10, 1931, Serial No. 562,087

2 Claims.

This invention relates to improvements in tumbler locks and has as a general object to provide a practical and effective method of grand master keying several master key series of such locks.

The locks to which this invention is directed are of the flat tumbler type. These locks are masterkeyed by providing each tumbler with two key engaging portions or steps preferably one on each side of the tumbler center, and by forming the pass keys and the master key with tumbler engaging ribs at opposite sides of the center of the key. The key engaging steps of all of the tumblers on one side are engaged by the rib of the'regular or pass key and the steps on the other sides of the tumblers are engaged by the master key.

This method of master-keying the locks is simple and effective, but heretofore, it has been impossible to grand master key several master use of three locations of ribs and three sets of key engaging steps on the tumblers, is that under certain conditions a tumbler would have its middle step projecting beneath its side steps which would result in a small projection or lug very susceptible to being struck over or bent during the insertion of the key having its tumbler engaging rib medially located. It is therefore a further object of this invention to provide a method of grand master keying several master series of locks in which the objections heretofore noted are entirely overcome and in which the simplicity and effectiveness of the present system of master keying is not disturbed.

More specifically it is an object of this invention to provide means for grand master keying several master series of locks whereby the same key engaging steps of the tumblers which are acted upon by the regular or pass key and the master key are also engaged by the grand master key.

And a still further object of this invention is to arrange the tumblers of the locks of several blers acted upon by the master key, remain the same in all of the locks, so that a grand master key provided with a dual bitting will engage the steps acted upon by the pass key and the steps engaged by the master key to lift all-of the 6 tumblers.

With the above and other objects in view which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

In the accompanying drawings, one complete example of the physical embodiment of this invention is illustrated constructed according to the best mode so far devised for the practical application of the principles thereof, and in which:

Figure 1 is a side elevation of a conventional fiat tumbler lock cylinder of the type to which this invention is directed;

Figure 2 is a cross section view taken through Figure 1 on the plane of the line 22 with the regular or pass key in position;

Figure 3 is a View similar to Figure 2, but with the master key in position;

Figure 4 is a perspective view of the tumblers of the lock cylinder shown in Figure I removed therefrom and in their proper order as viewed from the front of the cylinder;

Figure 5 is a perspective view of the pass key which conforms to the arrangement of tumblers shown in Figure 4;

Figure 6 is a perspective view of the master key conforming to the arrangement of tumblers in Figure 4;

Figure 7 is a diagram representing several master series of key changes, the locks of all of which respond to a single grand master key;

Figure 8 is a diagram representing the hitting of the grand master key;

Figure 9 is a side elevation of the grand master key; and

Figure 10 is a top view of the grand master key.

Referring now more particularly to the accompanying drawings in which like numerals indicate like parts throughout the several views, the numeral 5 represents the cylinder of a conventional fiat tumbler type lock in which a plurality of flat tumblers 6 are mounted. The tumblers 6 are spring urged by expansive springs '7 to project their ends 8 beyond the periphery of the cylinder. The projection of the tumblers by the springs 7 may be limited in any suitable manner, not shown, to preclude detachment of the tumblers from the cylinder. All of the tumblers have key openings 9 which register with a keyway 10 in the cylinder to permit the insertion of a key 11.

As is well known the key 11 has an irregularly shaped cross section which conforms to the shape of the outer end of the keyway 10 so that only a key having the proper cross section may be inserted into the keyway. The top edge of the key is serrated or cut to form depressions and raised portions which engage the top edge of the tumbler openings 9 to lift the tumblers against the action of their springs.

When the proper key is used i. e. one in which the formation of its top serrated edge, which is termed the bite, of the key, corresponds to the arrangement of the tumblers in the cylinder, all of the tumblers are raised sufliciently to bring their ends flush with the cylindrical surface of the cylinder. From this it follows that the distances between the top of the key openings 9 in the tumblers and the adjacent end of each tumbler must bear a predetermined relationship to its respective position on the key tumbler engaging rib and for convenience in manufacturing, these distances between the tops of the openings 9 in the tumblers and their adjacent ends, and the corresponding heights of their respective positions on the key, are made in a definite number of steps. In the present instance, there are three steps, i. e. the tumbler engaging portions of the key are at either of three distances from the straight bottom edge of the key and the distance between the tops of the openings 9 and the adjacent ends of the tumblers is one of three lengths.

If no attempt is to be made at master keying the series of locks, the top edges of the openings in the tumblers may be straight across the full width of the openings, but if it is desired tomas ter key a series of locks the top edges of the tumbler openings are provided with two key engaging steps and all of the pass keys have their key engaging ribs on one side of the center of the key and the master key has its key engaging rib on the opposite side of the center of the key, so that the ribs of the pass keys engage all of the tumbler steps on one side and the master key engages all of the tumbler steps on the other side.

This condition is clearly illustrated in Figures 2 and 3. Both views are taken on the same plane of Figure 1 and show the same tumbler acted upon by the pass key and the master key, respectively. one pass key is the same as that illustrated in Figure 1 and has its tumbler engaging rib 12 on the right side of the key center to engage all of the tumbler steps 13 on the right side of the tumbler longitudinal centers when viewed from the front of the lock, and the master key 14, as shown in Figure 3, has its tumbler engaging rib 15 on the left side of the center of the key to engage all of the tumbler steps 16 on the left side of their longitudinal centers. In this manner, it is possible to have a large number of combinations, each responding to a different pass key but all of which are operable by a single master key. All of the locks responding to one master key are thus considered as belonging to one master series.

Obviously there may be many master series, all of the locks in each series responding to the master key of that particular series, but to grand master all of the locks of the several master series by adding a third step and a third rib location, is impractical for the reasons hereinbeforestated.

This invention however contemplates a method of grand master keying several master series or locks without resorting to the use of a third step on the tumblers and a corresponding third rib location on the key, and to this end the tumbler combinations of the locks are arranged in a novel manner now about to be described.

As hereinbefore stated, the distances between the tops of the tumbler openings and the adjacent ends of the tumblers and heights of the key bittings are at either one of three lengths and these three distances or positions may be considered as stations with the shortest distance between the upper edge of the tumbler opening and its adjacent end, and the highest tumbler engaging portion on the key as station 1, the greatest distance between the upper edge of the tumbler opening and the adjacent tumbler end and the lowest tumbler engaging portion on the key, as station 3, and the intermediate distance and tumbler engaging portion, on the tumbler and key respectively, as station 2.

Figure l illustrates the relationship of these numbered stations to the actual configuration of the tumbler openings. It is observed that there are two sets of numbers, one representing the stations or steps engageable by the pass key and the other representing the stations or steps engageable by the master key, with those steps on the left hand side conforming to the bitting of the master key and those on the right hand side corresponding to one pass key.

From Figure 4, the graphical representation of the various combinations shown in Figure 7 is apparent. In this chart there are ten master series shown with from two to six locks in each series. Each set of numbers represents one look or combination with the upper row of numbers depicting the master key change and the lower row of numbers representing the pass key change. The combinations of the pass key of each series are different, but the combinations of the master key in all of the locks of any one series are the same.

It is observed that the first, third and last digits of all of the master keys are alike and that the second and fourth digits of all of the pass keys of the entire ten series are alike. This results in a combination which is found in each lock of the entire ten series. This combination employs stations from the pass key and master key sides as graphically illustrated in Figure 8.

A grand master key having tumbler engaging portions on both sides of its center, as shown in Figures 9 and 10, and in which the composite steps correspond to the combination depicted in Figure 8 will engage each tumbler and lift the same the proper distance; so that a grand master key constructed in this manner will operate any of the locks represented in Figure '7.

Analyzing the combination represented in Fig ure 8 it is seen that the left hand, or master key engaging step on the first tumbler of any lock represented in Figure 7 is at station 1, and respondsto the portion 17 of the key shown in Figures 9 and 10, the right hand or pass key engaging step on the second tumbler of any lock represented in Figure '7 is at station 2 and thus responds to the portion 18 of the grand master key, the left hand master key step of the third tumbler of any lock represented in Figure '7 is at the third station and responds to the portion 19 on the grand master key, the right hand or pass key step of the fourth tumbler of any lockrepresented in Figure '7 is at the third station and responds to the portion 20 of the grand master key, and lastly, the left hand or master key step of the innermost or fifth tumbler of any lock represented in Figure 7 is at the first station and responds to the portion 21 of the grand master key.

Each tumbler is thus acted upon by the grand master key through its engagement with either one or the other of the tumbler steps, and in this manner a simple and eflicient method of grand master keying several master series is obtained.

What I claim as my invention is:

1. In a tumbler lock, a lock cylinder, tumblers provided with a plurality of key engaging portions, said tumblers being arranged in the cylinder with the key engaging portions of the tumblers aligned to form a plurality of key change combinations, each properly responsive to a key engaging all of the key engaging portions of one combination, and the key engaging portions of one combination of certain of the tumblers and the key engaging portions of another combination of the remaining tumblers being properly responsive to a key bitted to engage said key engaging portions of said different combinations.

2. In locks of the character described, the combination of tumblers each having two key engaging portions so that two key change combinations are provided, each responsive to a key bitted to one combination, said tumblers being arranged to be responsive to a third key bitted to the key engaging portions of one combination of some of the tumblers and to the key engaging portions of the other combination of the remaining tumblers.

HUGO G. RUBNER. 

